Single-use containers are commonly used for providing small quantities of sterile, preservative-free liquids, e.g. lubricating eye drops. Commercial examples of such containers are used in the following products: Dry Eye Therapy.RTM. Lubricating Eye Drops from Bausch & Lomb; Tears Naturale Free.RTM. and Bion.RTM. Tears Lubricating Eye Drops from Alcon; Celluvisc.RTM. and Refresh PlusTM Lubricating Eye Drops from Allergan; OcuCoat.TM.PF Lubricating Eye Drops from Storz Opththalmics; and Hypo Tears.RTM. PF Lubricating Eye Drops from IOLAB.
Such containers are typically molded from low density polyethylene using form-fill seal or blow-fill seal technology. The containers include: a vessel portion for containing a small quantity of liquid, (e.g. typically from 0.1 to 3.0 ml), a twist-off seal top for sealing liquid within the vessel, and a neck portion interconnecting the seal top and vessel. To dispense liquid from the container, the seal top is bent, twisted or otherwise broken from the neck. The vessel is then squeezed between the finger tips to force liquid from the vessel and through the neck portion where droplets are formed. Once the liquid has been dispensed, the container is discarded.
A significant drawback to current single-use containers is they are not adapted for engagement between the finger tips, (e.g. between the forefinger finger tip and the finger tip of the thumb or other finger). That is, the outer surface of the vessel is egg-shaped, cylindrical, or wedge-shaped. As a consequence, when squeezing the vessel of current containers, the vessel tends to slip away from the opposing pressure of the finger tips. This problem is compounded with containers employing thicker vessel walls which are not easily deformed by squeezing. This situation is further compounded for persons suffering with arthritis or those otherwise having compromised hand and finger strength.
Another problem with current containers is the difficulty of removing the seal top. In order to avoid seal breakage during shipping and storage, the wall thickness of containers can be significant, thus making the seal tops difficult to remove. This problem is compounded by the small size of the seal top and its relatively smooth surface.
It is desired to provide a single-use container which provides greater ease of dispension. It is further desired to provide such a container which is more easily opened.